Uncontrolled satellites and debris in orbit about the Earth are an increasingly serious problem. In particular, such objects pose a risk of collision with other satellites and spacecraft. According to studies by NASA's debris office, controlling the propagation of the on-orbit debris environment can be accomplished by actively removing at least five large debris objects such as rocket bodies, boosters and derelict spacecraft per year. However, such objects are difficult to capture and move, either out of orbit or into orbits considered safe. One difficulty is that some percentage of these objects remain spinning in orbit at relatively high rates, or acquire a spin, as a result of disturbance torques which act on the object.
In order to actively remove these objects from orbit, many studies have considered using a secondary spacecraft to approach, rendezvous and dock with the target and, using an applied thrust, change their combined orbit so that the object will reenter Earth's atmosphere within 25 years or less. The difficulty of proximity operations increases dramatically as the spin rate of the target object increases. Decreasing the spin rate of the target object would allow more time for sensor data processing, which would significantly decrease the processing requirements for the active spacecraft and also dramatically decrease its propulsion requirements. However, the ability to decrease the spin rate of objects in space has been limited.